From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Shelley Vohr <shelley.vohr@gmail.com>
Date: Mon, 16 Aug 2021 17:55:32 +0200
Subject: fix: media key usage with globalShortcuts

This patch enables media keys to work properly with Electron's globalShortcut
module. Chromium's default usage of RemoteCommandCenterDelegate on macOS falls
down into MPRemoteCommandCenter, which makes it such that an app will not
receive remote control events until it begins playing audio. This runs
counter to the design of globalShortcuts, and so we need to instead
use `ui::MediaKeysListener`.

diff --git a/chrome/browser/extensions/global_shortcut_listener.cc b/chrome/browser/extensions/global_shortcut_listener.cc
index 91226bd6e383636ecebdac93b151e107b3f943d9..7fe79f49484b50d2ae9a8d5d0ba9749c62464378 100644
--- a/chrome/browser/extensions/global_shortcut_listener.cc
+++ b/chrome/browser/extensions/global_shortcut_listener.cc
@@ -8,6 +8,7 @@
 #include "base/not_fatal_until.h"
 #include "base/notreached.h"
 #include "content/public/browser/browser_thread.h"
+#include "content/public/browser/media_keys_listener_manager.h"
 #include "ui/base/accelerators/accelerator.h"
 
 using content::BrowserThread;
@@ -67,6 +68,22 @@ void GlobalShortcutListener::UnregisterAccelerator(
     StopListening();
 }
 
+// static
+void GlobalShortcutListener::SetShouldUseInternalMediaKeyHandling(bool should_use) {
+  if (content::MediaKeysListenerManager::
+            IsMediaKeysListenerManagerEnabled()) {
+    content::MediaKeysListenerManager* media_keys_listener_manager =
+        content::MediaKeysListenerManager::GetInstance();
+    DCHECK(media_keys_listener_manager);
+
+    if (should_use) {
+      media_keys_listener_manager->EnableInternalMediaKeyHandling();
+    } else {
+      media_keys_listener_manager->DisableInternalMediaKeyHandling();
+    }
+  }
+}
+
 void GlobalShortcutListener::UnregisterAccelerators(Observer* observer) {
   CHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   if (IsShortcutHandlingSuspended())
diff --git a/chrome/browser/extensions/global_shortcut_listener.h b/chrome/browser/extensions/global_shortcut_listener.h
index f96af14cb915c8ab92b314ac15b6dffcdd6ec607..2556abe433493251ebd48d4aeddaa6d4f553208f 100644
--- a/chrome/browser/extensions/global_shortcut_listener.h
+++ b/chrome/browser/extensions/global_shortcut_listener.h
@@ -33,6 +33,8 @@ class GlobalShortcutListener {
 
   static GlobalShortcutListener* GetInstance();
 
+  static void SetShouldUseInternalMediaKeyHandling(bool should_use);
+
   // Register an observer for when a certain |accelerator| is struck. Returns
   // true if register successfully, or false if 1) the specificied |accelerator|
   // has been registered by another caller or other native applications, or
diff --git a/content/browser/media/media_keys_listener_manager_impl.cc b/content/browser/media/media_keys_listener_manager_impl.cc
index b447847dc16ed4ddc8db14474fa24d880429b3c7..e72cab48bc1a60dc1c1a1a4c97e1be7d15bfb261 100644
--- a/content/browser/media/media_keys_listener_manager_impl.cc
+++ b/content/browser/media/media_keys_listener_manager_impl.cc
@@ -88,7 +88,11 @@ bool MediaKeysListenerManagerImpl::StartWatchingMediaKey(
       CanActiveMediaSessionControllerReceiveEvents();
 
   // Tell the underlying MediaKeysListener to listen for the key.
-  if (should_start_watching && media_keys_listener_ &&
+  if (
+#if BUILDFLAG(IS_MAC)
+      !media_key_handling_enabled_ &&
+#endif  // BUILDFLAG(IS_MAC)
+      should_start_watching && media_keys_listener_ &&
       !media_keys_listener_->StartWatchingMediaKey(key_code)) {
     return false;
   }
@@ -362,6 +366,20 @@ void MediaKeysListenerManagerImpl::StartListeningForMediaKeysIfNecessary() {
         this, ui::MediaKeysListener::Scope::kGlobal);
     DCHECK(media_keys_listener_);
   }
+
+#if BUILDFLAG(IS_MAC)
+  // Chromium's implementation of SystemMediaControls falls
+  // down into MPRemoteCommandCenter, which makes it such that an app will not
+  // will not receive remote control events until it begins playing audio.
+  // If there's not already a MediaKeysListener instance, create one so
+  // that globalShortcuts work correctly.
+  if (!media_keys_listener_) {
+    media_keys_listener_ = ui::MediaKeysListener::Create(
+        this, ui::MediaKeysListener::Scope::kGlobal);
+    DCHECK(media_keys_listener_);
+  }
+#endif
+
   EnsureAuxiliaryServices();
 }
 
